Sonerilas are a diverse group of plants in the Melastomaceae family distinguished by having flowers with three petals (as opposed to five for most other plants in this group). There seems to be a lot of variation within a species, and so the ID of pulchella is a guess.
This Malaysian Sonerila has striking green and pink foliage which just gets more pronounced as the plant matures. I just got it this year so am not entirely sure how large it gets.
And the flower,
Sonerila pulchella
Sonerila pulchella
